X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 04 May 2009 20:59:09 -0400 Message-ID: X-Original-Return-Path: Received: from web81508.mail.mud.yahoo.com ([68.142.199.148] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with SMTP id 3631276 for lml@lancaironline.net; Mon, 04 May 2009 09:09:13 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.199.148; envelope-from=kneadedpleasures@sbcglobal.net Received: (qmail 1377 invoked by uid 60001); 4 May 2009 13:08:39 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=G63PJFbZe4Py9/y9LPRtORvbV5uHZYVJQrEhOJk/CMVIhp+5kp39nCHY7CHEZNdTNkAk8GvdwO6JfE6ZS6nYbgoPaBFtwKxWIGh5xIRuuv8TJVpH8Sm99ZyH8L27yPWfHu1iJ1AcRCzUVQ1n779L2V8AvVUh2vfzSVQ/nFaPMpI=; X-Original-Message-ID: <991967.99816.qm@web81508.mail.mud.yahoo.com> X-YMail-OSG: ijtbxCgVM1neaRPmn5TLmsO4zXiF4ZXkehudFJGl_NwgIr.Hcdm5YSky11cCbOM4BN.Fp18TeuPALsGN3OSuzYQYNVsxM2MhkT12VVucxDYn9XTyIPttmfhlwrmhYBDnzEhYdZWuR7f4IbsUq1djBYAc07Z48dajpujvvQAKQfSBz64AgboKixZyVrWkUqBwP_MrZQ6LGj0oPD_7y1qvXLeLWvenLsmxGYtlhsZ4KgxR_QXYjMrvI_lBJ7zlK2NwzDY9EW8O.Gq.afvMsKlMoZXVxTvn6eAMC6vwCw-- Received: from [71.145.134.117] by web81508.mail.mud.yahoo.com via HTTP; Mon, 04 May 2009 06:08:38 PDT X-Mailer: YahooMailWebService/0.7.289.1 X-Original-Date: Mon, 4 May 2009 06:08:38 -0700 (PDT) From: kneaded pleasures Reply-To: kneadedpleasures@sbcglobal.net Subject: Flap Bracket Attach Bolts Too Short on 320/360 aircraft. X-Original-To: List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-6689472-1241442518=:99816" --0-6689472-1241442518=:99816 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable For more than a year I have been repainting my 360.=A0=A0On=A0reinstalling = the flap to the flap push-rod bracket, I stripped (too easily) a nut plate = inside of the flap.=A0 With the best surgeon-like precision I could muster,= I cut a whole in the=A0inboard end of the flap to remove/replace the strip= ped nut-plate.=A0=A0None of the bolts extended to the surface of the nut- p= lates and none was=A0closer than 3 threads from the surface -of course=A03 = threads should be showing beyond the end of the nut-plate.=A0 I had used=A0= the proper AN3-7A bolts called for in the plans (page 10-20).=A0 Further, I= believe=A0I had used (15 years ago) the recommended procedures for constru= cting that bulkhead -meaning the flap forward bulkhead=A0is=A0of proper thi= ckness =A0 My conclusion is that=A0many 320 and 360 aircraft are flying with bolts too= short to take advantage of the full strength of the nut-plates.=A0 Those b= olts are in tension when the flap is retracted and in shear and/or tension = when the flap is fully extended.=A0 Always those flaps are in high stress a= nd vibration environment. =A0 Recommendation:=A0 Check the length of=A0penetration of these bolts on your= next annual.=A0 Use an AN3-8A if the present bolts are too short to extend= beyond the embedded nut-plates.=A0 =A0 As incentive to remember to check these bolts at your next annual, think of= =A0of those bolts=A0 the next time you extend your flaps in flight.=A0=A0= =A0 Greg Nelson --0-6689472-1241442518=:99816 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
For more than a year = I have been repainting my 360.  On reinstalling the flap to = the flap push-rod bracket, I stripped (too easily) a nut plate inside of th= e flap.  With the best surgeon-like precision I could muster, I cut a = whole in the inboard end of the flap to remove/replace the stripped nu= t-plate.  None of the bolts extended to the surface of the nut- p= lates and none was closer than 3 threads from the surface -of course&n= bsp;3 threads should be showing beyond the end of the nut-plate.  I ha= d used the proper AN3-7A bolts called for in the plans (page 10-20).&n= bsp; Further, I believe I had used (15 years ago) the recommended proc= edures for constructing that bulkhead -meaning the flap forward bulkhead&nb= sp;is of proper thickness
 
My conclusion is that many 320 and 360 aircraft are flying with b= olts too short to take advantage of the full strength of the nut-plates.&nb= sp; Those bolts are in tension when the flap is retracted and in shear and/= or tension when the flap is fully extended.  Always those flaps are in= high stress and vibration environment.
 
Recommendation:  Check the length of penetration of these bo= lts on your next annual.  Use an AN3-8A if the present bolts are too s= hort to extend beyond the embedded nut-plates. 
 
As incentive to remember to check these bolts at your next annual, thi= nk of of those bolts  the next time you extend your flaps in flig= ht.    Greg Nelson
--0-6689472-1241442518=:99816--